Novartis announced the CRL Friday, saying the US regulator wanted more efficacy information than the Phase-II and Phase-III safety and efficacy data that accompanied the filing.

Although the FDA does not have to adhere to advisory panel recommendations, Friday's news synchs with an FDA panel's March vote against the drug, which rang in at 11-0.

Novartis is not giving up on the drug, despite Friday's announcement and the European Medicines
Agency's rejection in January. Instead, the company said it will expand the data set with a patient pool that will ultimately include 6,300 patients worldwide.